KR20160070093A - Wet process ceria compositions for polishing substrates, and methods related thereto - Google Patents

Abstract

A chemical-mechanical polishing composition and a polishing method for the substrate are disclosed. The polishing composition comprises a wet-process ceria abrasive particle, at least one alcohol amine, and water having a low average particle size (e.g., 30 nm or less), wherein the polishing composition has a pH of 6. Abrasive composition can be used, for example, to polish a polysilicon wafer used in any suitable substrate, such as the semiconductor industry.

Description

WET PROCESS CERIA COMPOSITIONS FOR POLISHING SUBSTRATES AND METHODS RELATED THERETO BACKGROUND OF THE INVENTION < RTI ID = 0.0 > [0001] <

Compositions and methods for planarizing or polishing the surface of a substrate are well known in the art. A polishing composition (also known as a polishing slurry) is typically applied to a surface by containing the polishing material in a liquid carrier and contacting the surface with a polishing pad saturated with a polishing composition. Typical abrasive materials include silicon dioxide, cerium oxide, aluminum oxide, zirconium oxide, and tin oxide. The polishing composition is typically used in conjunction with a polishing pad (e.g., polishing pad or disk). Instead of, or in addition to being suspended in the polishing composition, an abrasive material may be incorporated into the polishing pad.

The shallow trench isolation (STI) process is a method of isolating elements of a semiconductor device. In the STI process, a polysilicon layer is formed on the silicon substrate, a shallow trench is formed through etching or photolithography, and a dielectric layer (e.g., oxide) is deposited to fill the trench. Due to the change in trench or line depth formed in this manner, it is typically necessary to deposit an excess of dielectric material on top of the substrate to ensure complete filling of all the trenches.

Excess dielectric material is then typically removed by a chemical-mechanical planarization process to expose the polysilicon layer. When the polysilicon layer is exposed, the maximum area of the substrate exposed to the chemical-mechanical polishing composition comprises polysilicon, which must then be polished to achieve a very smooth and uniform surface. Thus, the polysilicon layer functions as a stop layer during the chemical-mechanical planarization process because the overall polishing rate decreases upon exposure of the polysilicon layer.

The STI substrate is typically polished using conventional polishing compositions. However, it has been observed that polishing the STI substrate with conventional polishing compositions causes excessive polishing of the substrate surface or recesses in the STI topography and the formation of other topographical defects such as micro-scratches on the substrate surface. Excessive polishing of the substrate may also cause loss of oxides and exposure of the underlying oxide to abrasion or damage from chemical activity, which adversely affects the quality and performance of the device.

A polishing composition that exhibits desirable planarization efficiency, uniformity, and removal rate during polishing and planarization of substrates such as semiconductors, particularly polysilicon substrates, while minimizing defects such as surface defects and damage to underlying structures and topography during polishing and planarization And a polishing method. The present invention provides such polishing compositions and methods. These and other advantages of the invention, as well as additional features of the invention, will become apparent from the description of the invention provided herein.

BRIEF SUMMARY OF THE INVENTION [

In one aspect, the present invention relates to a process for the preparation of (a) wet-process ceria abrasive particles having an average particle size of 30 nm or less, (b) at least one alcohol amine, and (c) water, , Or a chemical-mechanical polishing composition comprising the same and having a pH of 6 or more.

In yet another aspect, the present invention provides a method of polishing a substrate. (A) a wet-process ceria abrasive particle having an average particle size of 30 nm or less, (b) at least one alcohol amine, and (c) water, RTI ID = 0.0 > polishing < / RTI > The method further comprises moving the polishing pad and the polishing composition relative to the substrate to abrade at least a portion of the substrate to polish the substrate.

Figure 1 shows the polishing composition of Example 1 of the present invention for pH (X-axis), 2-dimethylamino-2-methylpropanol (DMAMP) concentration (Y-axis), and polysorbate 20 concentration Is a cube plot of high density plasma (HDP) removal rate.
Figure 2 is a square plot of the tetraethylorthosilicate (TEOS) removal rate of the polishing composition of Example 2 herein for polysorbate 20 concentration (X-axis) and triethanolamine concentration (Y-axis).
3 is a line graph of pitch length (X-axis) versus dishing (Y-axis) at 50% density of the polishing composition of Example 2 of the present application.
4 is a bar graph of the TEOS, HDP, and polysilicon removal rates (Y-axis) of the polishing composition (X-axis) of Example 3 of the present application.
5 is a line graph of pitch length (X-axis) vs. dishing (Y-axis) at 50% density of the polishing composition of Example 3 of the present application.
6 is a bar graph of TEOS, HDP, and polysilicon removal rates (Y-axis) of the polishing composition (X-axis) of Example 4 of the present application.
7 is a bar graph of the TEOS, HDP, and polysilicon removal rates (Y-axis) of various polishing compositions (X-axis) of Example 6 herein.
8 is a box plot of the random defect count (DCN) (Y-axis) of the polishing composition of Example 6 herein at different threshold values (X-axis).

DETAILED DESCRIPTION OF THE INVENTION [

Embodiments of the present invention comprise (a) wet-process ceria abrasive particles having an average particle size of 30 nm or less, (b) at least one alcohol amine, and (c) water, And a chemical-mechanical polishing composition comprising these, wherein the pH of the chemical-mechanical polishing composition is at least 6. Such a polishing composition may be present in the form of a slurry and may be polished with any suitable substrate, such as a mechanically weak surface (e.g., a polysilicon), with a suitable chemical-mechanical polishing (CMP) device including a polishing pad as described herein .

In some embodiments, the polishing composition achieves a high removal rate of the dielectric layer (e.g., oxide). Additionally, in some embodiments, the polishing composition achieves a low removal rate of polysilicon and / or silicon nitride. Additionally, in some embodiments, the polishing composition achieves a high removal rate of the dielectric layer while simultaneously achieving a low removal rate of polysilicon and / or silicon nitride. Additionally, in some embodiments, the polishing composition exhibits uniformity in the loss of material present on the substrate. As used herein, the term "uniformity " refers to a measure of the total loss of material on a substrate from a particular area of the substrate (e.g., edge, middle, center of the substrate) Where closer values correspond to greater uniformity. Additionally, in some embodiments, the polishing composition exhibits a low dishing within the dielectric layer trenches. As used herein, the term "dishing" refers to the degree to which a recess is formed in a trench filled with a dielectric layer. Dishing is measured by measuring the difference in height between the dielectric-filled trench and the adjacent topography (e.g., the polysilicon topography). Dishing can be measured by an elliptically polarized reflection method known to a person skilled in the art. Further, in some embodiments, the polishing composition achieves a low defectivity on the substrate to be polished. As used herein, the term "defective" refers to the number of defects (e.g., scratches) present on the substrate after polishing the substrate with the polishing composition. The defectiveness can be measured by a scanning electron microscope method known to a person skilled in the art.

The chemical-mechanical polishing composition comprises a ceria abrasive. As is known to those of ordinary skill in the art, ceria is an oxide of rare earth metal cerium and is also known as cerium oxide, cerium oxide (e.g., cerium (IV) oxide), or cerium dioxide. Cerium oxide (IV) (CeO ₂₎ it may be formed by calcining a cerium oxalate or cerium hydroxide. Cerium also forms the cerium oxide (III), for example, such as Ce ₂ O _3. The ceria abrasive may be any one or more of these or other oxides of ceria.

The ceria abrasive may have any suitable type. Preferably, the ceria abrasive is a wet-process ceria. As used herein, a "wet-process" ceria refers to a ceria prepared by precipitation, condensation-polymerization, or similar processes (as opposed to, for example, fumed or exothermic ceria). For example, in some embodiments, the wet-process ceria is formed by precipitating a cerium-containing precursor by controlling the precipitation to adjust the pH and pressure to achieve a controlled particle size. Thus, wet-process techniques can be used to improve particle growth in this manner, as opposed to the drying process techniques in which the calcining process is typically used to try and anneal cerium oxide from a ceria-containing precursor to achieve the desired degree of crystallinity By controlling, smaller particles can be generated.

It has been found that the polishing compositions of the present invention, including wet-process ceria abrasives, typically exhibit fewer defects when used to polish a substrate according to the method of the present invention. While not wishing to be bound by any particular theory, it is believed that the wet-process ceria comprises substantially spherical ceria particles and / or smaller aggregate ceria particles, thereby causing lower substrate defects when used in the method of the present invention . In addition, the same wet-process ceria particles described herein will contact the substrate, e.g., the wafer, with less momentum and energy, thereby reducing the size and frequency of defects such as scratches. An exemplary wet-process ceria is HC-60 (TM) ceria, commercially available from Rhodia, Cranbury, NJ.

For non-spherical particles, the size of the particles is the diameter of the smallest sphere containing the particles. The non-numerical phrase "particle size ", as used herein, may refer to one or both of primary and secondary particles. The primary particles refer to each such ceria particle dispersed in an aqueous carrier (e.g., water), while the secondary particles refer to aggregates of each ceria particle fused together in water. Particle size can be measured using any suitable technique, for example, using laser diffraction techniques known to those of ordinary skill in the art.

The ceria abrasive grains have a diameter of 40 nm or less, for example, 35 nm or less, about 30 nm or less, 29 nm or less, 28 nm or less, 27 nm or less, 26 nm or less, 25 nm or less, 24 nm or less, Any suitable suitable material having a thickness of 10 nm or less, 20 nm or less, 18 nm or less, 15 nm or less, 12 nm or less, 10 nm or less, 7 nm or less, 5 nm or less, 3 nm or less, 1 nm or less or 0.1 nm or less And may have an average particle size (i.e., an average particle size). Each of the above-mentioned end points may be, for example, a lower limit in the range of 0.1 nm to 40 nm, numerically suitably such as 0.1 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, It may have a lower limit of 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 30 nm, 35 nm or 39 nm. For example, the ceria abrasive grains may have a mean particle size of 0.1 nm to 40 nm, such as 14 nm to 24 nm, 18 nm to 23 nm, 17 nm to 21 nm, 3 nm to 27 nm, 5 nm to 26 nm, Or 30 nm, or 15 nm to 25 nm, and the like. Preferably, the ceria abrasive particles have an average particle size of 30 nm or less.

In some embodiments, the polishing composition may comprise ceria abrasive particles having an average primary particle size of 16 nm or less. The ceria abrasive particles may have a particle diameter of 16 nm or less, for example, 15 nm or less, 14 nm or less, 12 nm or less, 11 nm or less, 10 nm or less, 9 nm or less, 8 nm or less, 7 nm or less, 6 nm or less, Or less, 3 nm or less, or 1 nm or less. Each of the above-mentioned end points has a lower limit in the range of, for example, 0.1 nm to 16 nm, numerically suitably such as 0.1 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 10 nm, 12 nm, 14 nm, or 16 nm. For example, the ceria abrasive grains may have an average of 0.1 nm to 16 nm, such as 1 nm to 11 nm, 4 nm to 7 nm, 2 nm to 10 nm, 3 nm to 8 nm, or 5 nm to 9 nm It can have a primary particle size. Preferably, the ceria abrasive grains have an average primary particle size of 12 nm or less.

The ceria abrasive particles may be of any suitable average secondary particle size (for example, less than 40 nm, such as less than 35 nm, less than 30 nm, less than 29 nm, less than 28 nm, less than 27 nm, less than 26 nm, That is, an average particle diameter). Each of the above-mentioned end points may be, for example, a lower limit in the range of 25 nm to 40 nm, numerically suitably such as 25 nm, 26 nm, 27 nm, 28 nm, 29 nm, 30 nm, 35 nm, 39 nm, Or a lower limit of 40 nm. For example, the ceria abrasive grains may have an average secondary particle size of 25 nm to 40 nm, e.g., 26 nm to 35 nm, 27 nm to 30 nm, or 28 nm to 29 nm. Preferably, the ceria abrasive grains have an average secondary particle size of 30 nm or less.

According to some embodiments, the ceria abrasive particles are substantially free of agglomeration in the polishing composition. Aggregation will result in larger particle sizes in the polishing composition and therefore higher impact impacts on the substrate surface to be polished with the polishing composition. Thus, agglomeration can cause higher defectiveness on the substrate surface. As used herein, the phrase "substantially free" means aggregation without aggregation or a non-noticeable amount. A non-notable amount of aggregation can be, for example, less than or equal to 1 wt%, such as, for example, less than or equal to 0.5 wt%, less than or equal to 0.1 wt%, less than or equal to 0.01 wt%, or less than or equal to 0.001 wt% have.

The ceria particles are preferably colloidally stable in the polishing composition of the present invention. The term colloid refers to a suspension of abrasive particles in a liquid carrier. The colloidal stability refers to the retention of the suspension over time. In the context of the present invention, when the ceria abrasive is placed in a 100 ml graduated cylinder and allowed to stand without agitation for 2 hours, the concentration of the particles in the bottom 50 ml of the graduation cylinder (g / ml unit [B] ) Divided by the initial concentration of particles in the abrasive composition ([C] in g / ml), the difference between the concentration of the particles in the upper 50 ml of the calibration cylinder ([T] in g / ml) (I.e., {[B] - [T]} / [C] 0.5), the abrasive is considered to be colloidally stable. More preferably, the value of [B] - [T] / [C] is 0.3 or less, and most preferably 0.1 or less.

The ceria abrasive particles can be present in the polishing composition in any suitable amount. If the polishing composition of the present invention comprises too little ceria abrasive, the composition may not exhibit a sufficient removal rate. On the other hand, if the polishing composition comprises too much ceria abrasive, the polishing composition may exhibit undesirable polishing performance and / or may not be cost-effective and / or may lack stability.

Advantageously, in some embodiments, the ceria abrasive particles are present at a lower solids concentration than conventional systems, and this often exceeds 10-12 wt% solids. In accordance with embodiments of the present invention, the use of smaller amounts of ceria abrasive particles can result in lower defectiveness and significant cost savings.

For example, the ceria abrasive particles may be present at a concentration of at least 0.0005%, such as at least 0.001%, at least 0.005%, at least 0.01%, at least 0.05%, at least 0.1%, or at least 0.5% . Alternatively, or additionally, the ceria abrasive grains may comprise up to 10 wt%, such as up to 9 wt%, up to 8 wt%, up to 7 wt%, up to 5 wt%, up to 3 wt%, up to 2 wt% , Or 1% or less by weight of the polishing composition. Thus, the polishing composition may comprise ceria abrasive particles at a concentration within a limited range by any two of the above-mentioned end points. For example, the ceria abrasive may be present in an amount of from 0.0005% to 10%, such as from 0.1% to 1.0%, from 0.01% to 3.0%, from 0.005% to 7.0%, from 0.05% to 9.0% %, 0.5 wt% to 8.0 wt%, or 0.001 wt% to 5.0 wt%. Preferably, the ceria abrasive particles are present in the polishing composition at a concentration of from 0.001% to 2.0% by weight. In some embodiments, the ceria abrasive particles comprise less than or equal to 1 wt%, such as from 0.1 wt% to 1 wt%, such as from 0.1 wt% to 0.7 wt%, 0.1 wt% to 0.5 wt%, 0.1 wt% to 0.3 wt% (E. G. 0.2% by weight).

In some embodiments, an alcohol amine is included in the polishing composition to modify the surface properties of the substrate to be polished to make the substrate surface more receptive to interaction with the abrasive particles. The pH of the polishing composition plays an important role in determining the interaction between the polishing composition and the surface of the substrate to be polished. In some embodiments, alcohol amine is included to facilitate raising the pH of the polishing composition to a pH of at least about 6, 7 or more (e.g., a pH of 6 to 11) without destabilizing the ceria abrasive particles. In this regard, the native ceria particles can have a lower pH (e. G., 4), and the alcohol amine acts as a primary pH adjusting agent in the polishing composition to form a coagulated particle form It is possible to prevent the growth of particles. Thus, the presence of alcohol amine can reduce the onset of agglomeration of the ceria abrasive grains, which may otherwise occur at a pH of 6, and its precipitation.

The pH of the polishing composition may be any suitable pH of at least 6, such as at least 6.5, at least 7, at least 7.5, at least 8, at least 8.5, at least 9, at least 9.5, Further, the pH of the polishing composition may be up to 14, such as 13.5 or less, 13 or less, 12.5 or less, 12 or less, 11.5 or less, 11 or less, 10.5 or less, 10 or less, 9.5 or less, ≪ / RTI > Thus, the pH of the polishing composition may be within a limited range by any of the above-mentioned endpoints. For example, the pH of the polishing composition can be from 6 to 14, such as 6 to 10, 6 to 8, 6 to 7, 7 to 14, 7 to 10, or 8 to 12.

In order for the alcohol amine to interact with the substrate within this pH range, in some embodiments, the alcohol amine is preferably a functional group having a pKa (in water) of from 7 to 11, such as from 7.5 to 10, for example from 8 to 9 For example, an alcohol amine will act as a base in water. In some embodiments, the alcohol amine has an isoelectric point (pKi, also referred to as pI) of 6 to 10, such as 7.5 to 9, for example, 6.5 to 7.

The alcohol amine may be any suitable alcohol amine. Preferably, the alcohol amine is selected from the group consisting of 2-dimethylamino-2-methylpropanol (DMAMP), triethanolamine, diethanolamine, ethanolamine, 2-amino- , A co-formed product thereof, or a combination thereof.

Alcoholic amines may be present in any suitable concentration. For example, the alcohol amine can be present in a concentration of 0.0005 wt% or more, for example, 0.005 wt% or more, 0.01 wt% or more, 0.05 wt% or more, 0.1 wt% or more, or 0.5 wt% or more. Alternatively, or additionally, the alcoholamine may be present in the polishing composition at a concentration of up to 5% by weight, for example up to 4% by weight, up to 3% by weight, up to 2% by weight, or up to 1% by weight. Thus, the alcohol amine may be present in the polishing composition at a concentration within a limited range by any two of the above-mentioned end points. For example, the alcohol amine may be present in an amount of from 0.005 wt% to 5 wt%, such as from 0.01 wt% to 3 wt%, from 0.1 wt% to 2 wt%, from 0.005 wt% to 4 wt%, or from 0.05 wt% to 1 wt% %. ≪ / RTI > Preferably, the alcohol amine is present in the polishing composition at a concentration of from 0.001% to 1% by weight.

The pH of the polishing composition can be achieved and / or maintained by any suitable means. More specifically, the polishing composition may further comprise a secondary pH adjusting agent used alone or in combination with an alcohol amine, a pH buffer, or a combination thereof. The secondary pH adjusting agent may be any suitable pH-adjusting compound, for example, any suitable acid. Typically, the acid is acetic acid, nitric acid, phosphoric acid, oxalic acid, and combinations thereof. Preferably, the acid is nitric acid. The secondary pH adjuster may alternatively be a base. The base may be any suitable base. Typically, the base is potassium hydroxide, ammonium hydroxide, and combinations thereof. The pH buffer may be any suitable buffer. For example, the pH buffering agent may be a phosphate, a sulfate, an acetate, a borate, an ammonium salt, or the like. The polishing composition may comprise any suitable amount of a pH adjusting agent and / or a pH buffer, with suitable amounts being used to achieve and / or maintain the pH of the polishing composition within the pH ranges described herein.

Optionally, in some embodiments, the polishing composition may comprise at least one nonionic surfactant. The nonionic surfactant may be any suitable nonionic surfactant. Preferably, the nonionic surfactant is selected from the group consisting of polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80, polysorbate 85, sorbitan, polyoxyethylene ether, ethoxylate, Block copolymers such as acrylic, polyetherpolyol, hydroformate 3233, sorbitan monolaurate, polyoxyethylene (40) nonylphenyl ether, pentaerythritol ethoxylate, glycerol propoxylate-block-ethoxylate, Propylene oxide-based triols, co-formed products thereof, or combinations thereof. In some embodiments, the nonionic polymer functions as a surfactant and / or a wetting agent. The presence of a non-ionic surfactant advantageously allows a useful removal rate for the dielectric layer (e.g., oxide) while reducing the removal rate for polysilicon. Additionally, the presence of a nonionic surfactant allows low dishing in some embodiments of the present invention. Further, in some embodiments of the present invention, the presence of a nonionic surfactant allows low defectivity on the substrate to be polished.

When present in the polishing composition, the nonionic surfactant may be present in the polishing composition at any suitable concentration. For example, the nonionic surfactant may be present at a concentration of 0.0005 wt% or more, for example, 0.005 wt% or more, 0.01 wt% or more, 0.05 wt% or more, 0.1 wt% or more, or 0.5 wt% or more. Alternatively, or additionally, the nonionic surfactant may be present in the polishing composition at a concentration of up to 5% by weight, for example up to 4% by weight, up to 3% by weight, up to 2% by weight, or up to 1% have. Thus, the non-ionic surfactant may be present in the polishing composition at a concentration in a limited range by any two of the above-mentioned endpoints. For example, the nonionic surfactant may be present in an amount of from 0.005 wt% to 5 wt%, such as from 0.01 wt% to 3 wt%, from 0.1 wt% to 2 wt%, from 0.005 wt% to 4 wt%, or from 0.05 wt% 1% < / RTI > by weight. Preferably, the nonionic surfactant is present in the polishing composition at a concentration of from 0.001% to 1% by weight.

The nonionic surfactant may have any suitable hydrophobic lipophilic balance (HLB). For example, the nonionic surfactant may have an HLB of 3 or more, such as 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, or 11 or more. Alternatively, or additionally, the nonionic surfactant may be present in an amount of 22 or less, such as 21 or less, 20 or less, 19 or less, 18 or less, 17 or less, 16 or less, 15 or less, 14 or less, 13 or less, Of the HLB. Thus, the nonionic surfactant may have a limited range of HLBs by any two of the above-mentioned endpoints. For example, the nonionic surfactant may have an HLB of 3 to 22, 4 to 21, 5 to 20, 6 to 19, 10 to 13, or 8 to 15. Preferably, the nonionic surfactant has an HLB of 7 to 18.

Optionally, in some embodiments, the polishing composition may comprise one or more thickeners. Thickening agents may be included and serve, for example, as a dishing reducing agent. The thickener may be any suitable thickener. Preferably, the thickening agent is selected from the group consisting of a cellulosic compound, dextran, polyvinyl alcohol, carrageenan, chitosan, hydroxyethylcellulose, carboxyethylcellulose, hydroxymethylcellulose, methylcellulose, hydroxypropylcellulose, It is his combination.

When present in the polishing composition, the thickener may be present in the polishing composition at any suitable concentration. For example, the thickener may be present in a concentration of 0.0005% by weight or more, such as 0.005% by weight or more, 0.01% by weight or more, 0.05% by weight or more, 0.1% by weight or more, or 0.5% by weight or more. Alternatively, or additionally, the thickener may be present in the polishing composition at a concentration of up to 5% by weight, for example up to 4% by weight, up to 3% by weight, up to 2% by weight, or up to 1% by weight. Thus, the thickening agent may be present in the polishing composition at a concentration range limited by any two of the above-mentioned endpoints. For example, the thickener may be present in an amount of from 0.005% to 5%, such as from 0.01% to 3%, from 0.1% to 2%, from 0.005% to 4%, or from 0.05% to 1% ≪ / RTI > Preferably, the thickener is present in the polishing composition at a concentration of from 0.001% to 1% by weight.

Optionally, in some embodiments, the polishing composition may comprise one or more cationic polymers that serve, for example, as removal rate promoters, defective reducing agents, or both. The cationic polymer may be any suitable cationic polymer. Preferably, the cationic polymer is selected from the group consisting of poly (methacryloxyethyltrimethylammonium) chloride (poly MADQUAT), poly (diallyldimethylammonium) chloride (poly DADMAC), poly (acrylamide) Vinyl imidazolium), poly (vinyl pyridinium), a co-formed product thereof, or a combination thereof.

When present in the polishing composition, the cationic polymer can be present in the polishing composition at any suitable concentration. For example, the cationic polymer may be present at a concentration of at least 0.0005 wt%, such as at least 0.005 wt%, at least 0.01 wt%, at least 0.05 wt%, at least 0.1 wt%, or at least 0.5 wt%. Alternatively, or additionally, the cationic polymer can be present in the polishing composition at a concentration of up to 5% by weight, for example up to 4% by weight, up to 3% by weight, up to 2% by weight, or up to 1% by weight . Thus, the cationic polymer may be present in the polishing composition at a concentration range limited by any two of the above-mentioned end points. For example, the cationic polymer may comprise from 0.005% to 5%, such as from 0.01% to 3%, from 0.1% to 2%, from 0.005% to 4%, or from 0.05% to 1% % ≪ / RTI > by weight. Preferably, the cationic polymer is present in the polishing composition at a concentration of from 0.001% to 1% by weight.

Optionally, the polishing composition further comprises at least one additive. Exemplary additives include conditioners, acids (e.g., sulfonic acids), complexing agents (e.g., anionic polymeric complexing agents), chelating agents, biocides, scale inhibitors, dispersants and the like.

The biocide can be any suitable biocidal agent and can be present in any suitable amount in the polishing composition. A suitable biocide is an isothiazolinone nonbiocide. The amount of biocide used in the polishing composition is typically from 1 to 50 ppm, preferably from 10 to 20 ppm.

The polishing composition may be prepared by any suitable technique, many of which are known to those of ordinary skill in the art. The polishing composition may be prepared by a batch or continuous process. In general, polishing compositions can be prepared by combining the components described herein in any order. The term "component" as used herein is intended to encompass individual components (e.g., ceria abrasive, alcohol amine, water, optional nonionic surfactant, optional thickener, optional cationic polymer, and / (Such as a ceria abrasive, an alcohol amine, water, an optional nonionic surfactant, an optional thickener, an optional cationic polymer, etc.) as well as other additives (e.g., phosphorus additives).

For example, the polishing composition may comprise (i) providing all or part of a liquid carrier, and (ii) a ceria abrasive, an alcoholamine, water, an optional nonionic surfactant, an optional thickener, an optional cationic polymer, and / Or any optional additives in a liquid carrier using any suitable means for making such a dispersion, (iii) adjusting the pH of the dispersion appropriately, and (iv) optionally, Can be prepared by adding the phosphorus component and / or the additive to the mixture.

Alternatively, the polishing composition may comprise (i) one or more components (e.g., water, optional nonionic surfactant, optional thickener, optional cationic polymer, and / or optional optional additives) (Ii) providing in the additive solution one or more components (e.g., water, optional nonionic surfactant, optional thickener, optional cationic polymer, and / or any optional additives) (Iii) combining the cerium oxide slurry and the additive solution to form a mixture, (iv) optionally adding a suitable amount of any other optional additives to the mixture, and (v) adjusting the pH of the mixture appropriately . ≪ / RTI >

The polishing composition may be supplied as a one-packaged system comprising a ceria abrasive, an alcohol amine, an optional nonionic surfactant, an optional thickener, an optional cationic polymer, and / or any optional additives, and water. Alternatively, the polishing composition comprises a cerium oxide slurry and an additive solution, wherein the ceria oxide slurry comprises a ceria abrasive, an optional nonionic surfactant, an optional thickener, an optional cationic polymer, and / Package system, which is essentially comprised of, or consists of, a two-package system. The two-package system allows adjustment of the overall flattening characteristics of the substrate and the polishing rate by changing the blending ratio of the two packages, cerium oxide slurry and additive solution.

Various methods can be used to utilize this two-package polishing system. For example, the cerium oxide slurry and additive solution can be delivered to the polishing table by different pipes coupled and connected at the outlet of the feed piping. The cerium oxide slurry and the additive solution may be mixed just before or just before the polishing, or may be supplied simultaneously on the polishing table. In addition, when mixing two packages, deionized water may be added as needed to adjust the polishing composition and the resulting substrate polishing characteristics.

Likewise, a three-package, four-package, or more, package system may be used with the present invention, wherein each of the plurality of containers includes different components of the chemo-mechanical polishing composition of the present invention, Phosphorous, and / or different concentrations of the same component.

To mix the components contained in two or more storage devices and to produce a polishing composition at or near the point of use, the storage device typically contains a use-point of the polishing composition (e.g., platen, The polishing pad or the substrate surface itself). As used herein, the term "use-point" refers to the point (e.g., the polishing pad or substrate surface itself) where the polishing composition is applied to the substrate surface. The term "flow line" means a flow path from an individual storage vessel to the point of use of the components stored therein. The flow lines may each lead directly to a use-point, or two or more of the flow lines may be combined into a single flow line at any point leading to a use-point. In addition, any of the flow lines (e. G., Separate flow lines or combined flow lines) may be connected to one or more other devices (e. G., A pumping device, , Mixing device, etc.).

The components of the polishing composition can be delivered independently at the point of use (e.g., the component is delivered to the substrate surface and the resulting component is mixed during the polishing process), or one or more of the components Can be combined before delivery, for example, immediately before or immediately before delivery to a use-point. The components may be added in a mixed form on the platen, for example, in less than 4 minutes, less than 3 minutes, less than 2 minutes, less than 1 minute, less than 45 seconds (For example, the components are combined in a dispenser) at the same time as the delivery of the components at the "use-to-point" If the components are combined within 5 m of the use-point, for example within 1 m of the use-point or even within 10 cm of the use-point (for example within 1 cm of the use-point) Use - just before being delivered to the point ".

When two or more of the components of the polishing composition are combined before reaching the use-point, the components can be delivered to the use-point in a combined flow line without the use of a mixing device. Alternatively, one or more of the flow lines may lead to a mixing device to facilitate the combination of two or more of the components. Any suitable mixing device may be used. For example, the mixing device may be a nozzle or jet (e.g., high pressure nozzle or jet) through which at least two of the components flow. Alternatively, the mixing apparatus may comprise at least one inlet through which two or more components of the polishing slurry are introduced into the mixer, and at least one inlet through which the mixed components exit the mixer, either directly or through another member of the apparatus Type mixing device that includes at least one outlet through which it is delivered to the use-point (e.g., via the flow line). The mixing device may also comprise more than one chamber, each chamber having at least one inlet and at least one outlet, wherein two or more components are combined in each chamber. When a container-type mixing apparatus is used, the mixing apparatus preferably includes a mixing mechanism for facilitating the combination of components. Mixing mechanisms are generally known in the relevant art and include stirrers, blenders, agitators, paddled baffles, gas sparger systems, vibrators, and the like.

The polishing composition may also be provided as a concentrate intended to be diluted with an appropriate amount of water prior to use. In one such embodiment, the abrasive composition concentrate may be prepared by diluting the concentrate with a suitable amount of water, in an amount such that each component of the abrasive composition is present in the abrasive composition in an amount within the appropriate range mentioned above for each component ≪ / RTI > For example, ceria abrasive, alcohol amine, optional non-ionic surfactant, optional thickener, optional cationic polymer, and / or any optional additives may be present in the concentrate at a concentration of 2 (E.g., three times, four times, or five times), so that the concentrate can be present in equal volume of water (e. G., Two times each equivalent volume of water, three times equivalent volume of water, Or four times the equivalent volume of water), each component will be present in the polishing composition in an amount within the above-indicated ranges for each component. Additionally, as will be appreciated by one of ordinary skill in the art, the concentrate may be a mixture of ceria abrasive, alcohol amine, optional non-ionic surfactant, optional thickener, optional cationic polymer and / Water of the appropriate fraction present in the final polishing composition to ensure that it is at least partially or completely dissolved.

Embodiments of the present invention also provide a method of polishing a substrate with an abrasive composition of one embodiment described herein. The method of polishing a substrate includes the steps of (i) providing a substrate, (ii) providing a polishing pad, (iii) providing a polishing composition according to one embodiment of the present invention, (iv) (V) abrading the substrate by moving the polishing pad and the polishing composition against the substrate to wear at least a portion of the substrate.

In particular, some embodiments of the method comprise contacting the substrate with a polishing pad comprising (a) wet-process ceria abrasive particles having an average particle size of 30 nm or less, (b) at least one alcohol amine, and (c) With a polishing composition. The polishing composition has a pH of at least 6. The method further comprises moving the polishing pad and the polishing composition relative to the substrate to abrade at least a portion of the substrate to polish the substrate.

In the contacting step, the polishing composition is provided in an appropriate amount as would be appreciated by the ordinary skilled artisan.

The abrasion step is carried out for a suitable amount of time, for example, to achieve the desired abrasion of the substrate.

The polishing composition can be used to polish any suitable substrate and is particularly useful for polishing a substrate comprising at least one layer (typically a surface layer) comprised of a low dielectric material. Suitable substrates include wafers used in the semiconductor industry. The wafers typically comprise or consist of, for example, metals, metal oxides, metal nitrides, metal composites, metal alloys, low dielectric materials, or combinations thereof. The method of the present invention is particularly useful for polishing a substrate comprising silicon oxide and / or polysilicon such that some of the silicon oxide and / or polysilicon is removed from the substrate and the substrate is polished. The dielectric layer (e.g., silicon oxide) polished with the polishing composition of the present invention can have any suitable dielectric constant, such as less than 3.5, such as less than 3, less than 2.5, less than 2, less than 1.5, You can have a constant. Alternatively, or additionally, the dielectric layer may have a dielectric constant of at least 1, such as at least 1.5, at least 2, at least 2.5, at least 3, or at least 3.5. Thus, the dielectric layer may have a dielectric constant within a limited range by any two of the aforementioned endpoints. For example, the dielectric layer may have a dielectric constant of 1 to 3.5, such as 2 to 3, 2 to 3.5, 2.5 to 3, 2.5 to 3.5.

In certain embodiments, the substrate comprises polysilicon in combination with silicon oxide and / or silicon nitride. The polysilicon can be any suitable polysilicon, many of which are known in the art. The polysilicon can have any suitable phase and can be amorphous, crystalline, or a combination thereof. Silicon oxide may similarly be any suitable silicon oxide, many of which are known in the art. Suitable types of silicon oxide include borophosphosilicate glass (BPSG), plasma-enhanced tetraethylorthosilicate (PETEOS), tetraethylorthosilicate (TEOS), thermal oxides, undoped silicate glass, and high density Plasma (HDP) oxides, and the like.

The polishing composition preferably exhibits a high removal rate when polishing a substrate comprising silicon oxide according to the method of the present invention. For example, a silicon wafer comprising a high density plasma (HDP) oxide and / or plasma-enhanced tetraethylorthosilicate (PETEOS), spin-on-glass (SOG) and / or tetraethylorthosilicate (TEOS) The polishing composition preferably has a polishing rate of 400 A / min or more, for example, 700 A / min or more, 1,000 A / min or more, 1,250 A / min or more, 1,500 A / min or more, Min or more, at least 4,500 Å / min, at least 2,000 Å / min, at least 2,500 Å / min, at least 3,000 Å / min, at least 3,500 Å / min, at least 4,000 Å / min, at least 4500 Å / min, Lt; / RTI >

The polishing composition preferably exhibits a low removal rate when polishing a substrate comprising polysilicon and / or silicon nitride according to the method of the present invention. For example, when polishing a silicon wafer comprising polysilicon in accordance with one embodiment of the present invention, the polishing composition preferably has a thickness of less than or equal to 1,000 ANGSTROM / min, such as less than or equal to 750 ANGSTROM min Min and less than or equal to 250 A / min, less than or equal to 100 A / min, less than or equal to 50 A / min, less than or equal to 25 A / min, less than or equal to 10 A / min, or even less than or equal to 5 A / min .

For example, in some embodiments, the polishing compositions and methods of the present invention are useful in applications having polysilicon squares separated by silicon oxide trenches. In some embodiments, the polishing composition may be used for "NAND flash" polishing of non-volatile memory devices that are sensitive to defects, such as, for example, scratches, for stop-on-poly (SOP) applications. Preferably, in some embodiments, the use of the polishing composition and method according to the present invention may increase the yield of the wafers to 90% or more, for example, 92% or more, or 95% or more.

The polishing composition preferably exhibits low dishing as determined by suitable techniques when polishing the substrate. For example, if a patterned silicon wafer comprising trenches filled with a dielectric layer (e.g., oxide) is polished with an embodiment of the present invention, the polishing composition preferably has a thickness of less than or equal to 2500 angstroms, Less than 2000 Å, less than 1750 Å, less than 1500 Å, less than 1250 Å, less than 1000 Å, less than 750 Å, less than 500 Å, less than 250 Å, less than 100 Å, less than 50 Å or less than 25 Å.

The polishing composition preferably exhibits less particle defects as determined by suitable techniques when polishing the substrate. Particle defects on the polished substrate with the polishing composition of the present invention can be determined by any suitable technique. For example, using laser light scattering techniques, such as using a dark field normal beam composite (DCN) and a dark field oblique beam composite (DCO) The defect can be determined. Suitable devices for evaluating particle defectiveness are available, for example, from KLA-Tencor (e.g., SURFSCAN ™ SP1 instrument operating at 120 nm threshold or 160 nm threshold) .

Substrates polished with a polishing composition, particularly silicon containing silicon oxide and / or polysilicon, preferably have a dielectric constant of less than or equal to 20,000 counts, such as less than or equal to 17,500 counts, less than or equal to 15,000 counts, less than or equal to 12,500 counts, less than or equal to 3,500 counts, , 2,500 counts or less, 2,000 counts or less, 1,500 counts or less, or 1,000 counts or less. Preferably, the polished substrate according to one embodiment of the present invention has a DCN value of 750 counts or less, for example 500 counts, 250 counts, 125 counts, or even 100 counts or less.

The substrate polished with the polishing composition of one embodiment preferably exhibits a low total scratch count, as determined by suitable techniques. For example, the polishing composition preferably has a composition of less than or equal to 90 counts, such as up to 80 counts, up to 70 counts, up to 60 counts, up to 50 counts, up to 40 counts, up to 30 counts, up to 20 counts, up to 10 counts, 5 counts or less, 2 counts or less, or 1.5 counts or less.

When the polysilicon substrate is polished with the polishing composition of one embodiment, the loss of polysilicon from the substrate can be measured from the edge, middle, and center of the polysilicon substrate. When polishing the substrate, the polishing composition preferably exhibits uniformity of polysilicon loss, as determined by suitable techniques. For example, the polysilicon loss values from the edges, middle, and center of the polysilicon substrate are preferably within 50 angstroms of each other, e.g., within 40 angstroms of each other, within 30 angstroms of each other, within 20 angstroms of each other, Within 5 angstroms, within 2.5 angstroms, within 1.0 angstroms, or within 0.1 angstroms of one another.

The polishing composition can be tailored to provide selective efficient polishing for a particular material while minimizing surface imperfections, defects, corrosion, erosion and removal of the interrupted layer. Selectivity can be controlled to some extent by changing the relative concentrations of the components of the polishing composition. 1: 1, at least 15: 1, at least 25: 1, at least 50: 1, at least 100: 1, or even at least 150: The substrate can be polished with silicon dioxide in excess of polysilicon polishing selectivity. Certain formulations may exhibit much higher silicon oxide to polysilicon selectivity, such as 20: 1 or more, or even 30: 1 or more. For example, the removal rate (A / min) for silicon oxide may be at least 10 times higher than the removal rate for polysilicon.

According to the present invention, the substrate may be planarized or polished with the polishing composition described herein by any suitable technique. The polishing method of the present invention is particularly suitable for use with a CMP apparatus. Typically, a CMP apparatus includes a platen that moves when in use and has a velocity due to trajectory, linear, or circular motion, a polishing pad that contacts the platen and moves with the platen when in operation, By contacting and moving against the carrier. Embodiments of the polishing composition of the present invention allow increased platen speeds (e.g., greater than 50 rpm, such as greater than 100 rpm). Polishing of the substrate can be accomplished by placing the substrate in contact with the polishing composition of the present invention and preferably with the polishing pad and then abrading at least a portion of the surface of the substrate, e.g., one or more of the substrate materials described herein, with a polishing composition, .

The substrate may be polished with a polishing composition using any suitable polishing pad (e.g., a polishing surface). Suitable polishing pads include, for example, woven and nonwoven polishing pads. Further, suitable polishing pads may comprise any suitable polymer of varying density, hardness, thickness, compressibility, resilience upon compression, and compressive modulus. Suitable polymers include, for example, polyvinyl chloride, polyvinyl fluoride, nylon, fluorocarbon, polycarbonate, polyester, polyacrylate, polyether, polyethylene, polyamide, polyurethane, polystyrene, polypropylene , A co-formed product thereof, and mixtures thereof. A flexible polyurethane polishing pad is particularly useful with the polishing method of the present invention. Typical pads include, but are not limited to, SURFIN ™ 000, Surfin ™ SSW1, SPM3100 (commercially available, for example, from Eminess Technologies), POLITEX ™, and Fujibo ™ POLYPAS) < RTI ID = 0.0 > 27, < / RTI > A particularly preferred polishing pad is the EPIC D100 pad commercially available from Cabot Microelectronics.

Preferably, the CMP apparatus further comprises an in-situ polishing endpoint detection system, many of which are known in the art. Techniques for inspecting and monitoring the polishing process by analyzing light or other radiation reflected from the surface of the workpiece are known in the art. Such methods are described, for example, in U.S. Patent 5,196,353, U.S. Patent 5,433,651, U.S. Patent 5,609,511, U.S. Patent 5,643,046, U.S. Patent 5,658,183, U.S. Patent 5,730,642, U.S. Patent 5,838,447, U.S. Patent 5,872,633, U.S. Patent 5,893,796, U.S. Patent 5,949,927, 5,964,643. Preferably, the inspection or monitoring of the progress of the polishing process to the workpiece to be polished enables the determination of the polishing endpoint, that is, the determination when terminating the polishing process for a particular workpiece.

The following examples further illustrate the invention but, of course, should not be construed as limiting its scope in any way.

Example 1

This example illustrates the effect of pH, DMAMP, polysorbate, and wet-process ceria (average particle size) of 30 nm or less on the removal rate of silicon oxide from a homogeneous silicon oxide film (blanket wafer) polished with polishing composition 1A- Demonstrating the effect of abrasive particles. In this example, the abrasive composition comprises 6000 ppm polyethylene glycol (PEG) 8000, various amounts of polysorbate 20 and DMAMP-80 (as shown in Table 1A), and 2.4% wet process ceria Abrasive particles. In addition, the pH values of the polishing composition are listed in Table 1A. All combinations were tested in 0.43% solids.

Blanket wafers of tetraethylorthosilicate (TEOS) and high density plasma (HDP) were coated on a Mirra CMP device (Applied Materials, Inc., Santa Clara, Calif.) With abrasive composition 1A-1I . The polishing parameters of the Mirama (TM) process are shown in Table 1B below.

After polishing, the HDP removal rate for each polishing composition was measured in < RTI ID = 0.0 > A / min. ≪ / RTI > The results are shown in FIG. 1, which is a cube plot showing the HDP removal rates generated at the pH (X-axis), DMAMP level (Y-axis), and twin -20 level (Z-axis) of a given polishing composition.

Table 1A: Polishing composition summary

Table 1B: Mirror ™ process parameters

These results demonstrate that higher silicon oxide removal rates were obtained for polishing compositions with higher DMAMP levels. Particularly, the polishing composition 1G exhibited a removal rate that was about four times higher than that of the polishing composition 1C. The only difference in the two polishing compositions was that the DMAMP ppm of the polishing composition 1G was five times greater than the polishing composition 1C.

The results also demonstrate that lower pH is best for higher removal rates. Particularly, the polishing composition 1B had a removal rate 10 times higher than that of the polishing composition 1H. The only difference in the two polishing compositions was that polishing composition 1B was more acidic.

Additionally, the results show that higher polysorbate 20 levels increase the silicon oxide removal rate. In particular, the polishing composition 1C exhibited a removal rate that was approximately seven times higher than that of the polishing composition 1H. The only difference in the two polishing compositions was that 20 ppm of polysorbate was four times more abrasive composition 1C.

Example 2

This example demonstrates the effect of polysorbate, triethanolamine, and wet-process ceria abrasive grains having an average particle size of 30 nm or less on the removal rate of silicon oxide from a TEOS blanket wafer polished with Polishing Composition 2A-2E. In addition, this example measures that the dishing abrasive composition 2A-2E is produced in a patterned silicon oxide filled trench in a polished silicon film (patterned wafer) polished with abrasive composition 2A-2E. In this example, the polishing composition comprises 6000 ppm polyethylene glycol (PEG) 8000, various amounts of removal rate promoter triethanolamine and polysorbate 20 (as shown in Table 2A) and a 2.4% wet process with an average particle size of 30 nm or less Ceria abrasive grains. All combinations were tested in 0.43% solids.

The blanket wafer of TEOS was polished with Polishing Composition 2A-2E. Further, the patterned wafer was polished with the polishing composition 2A-2E. Polishing was performed on a Reflexion (TM) CMP device (Applied Materials, Inc., Santa Clara, Calif.). The polishing parameters of the Reflection ™ process are shown in Table 2B below.

Dishing was measured by an F5 ellipsometer reflector (KLA-Tencor, Milpitas, Calif.) By comparing the difference in thickness between the silicon oxide film in the trench and the surrounding polysilicon film, It corresponds to the singing rate.

After polishing, the TEOS removal rate was measured in < RTI ID = 0.0 > A / min < / RTI > and the result is shown in FIG. 2, which shows the polysorbate 20 level (X-axis) and triethanolamine (Y- Which is a plot showing the TEOS removal rate generated at the < RTI ID = 0.0 >

The dishing exhibited by each polishing composition was measured in Angstroms and is shown in Figure 3, which shows the dishing (Y-axis) measured within a pitch of various lengths (X-axis) at 50% density for each polishing composition .

Table 2A: Polishing composition summary

Table 2B: Reflection ™ process parameters

These results demonstrate that a higher TEOS removal rate is achieved for polishing compositions having lower triethanolamine levels regardless of the amount of polysorbate present in a given polishing composition. In particular, polishing compositions 2 D and 2 C had similar TEOS removal rates, although polishing composition 2 C contained 5 times the amount of polysorbate 20. The results also indicate that higher pH is detrimental to the removal rate, as demonstrated by the comparison of polishing compositions 2A and 2B, that higher triethanolamine contributed to higher pH levels and lower removal rates for certain polishing compositions Prove that.

In addition, the results demonstrate that the polishing composition of Table 2A exhibits poor dishing performance. More particularly, FIG. 3 illustrates dishing within various pitch sizes (measured in micrometers) at 50% density. Even at the smallest pitch size, all polishing compositions exhibited a dishing of greater than 1000 angstroms. Polishing composition 2B had the lowest dishing at various micrometer pitch sizes, suggesting that higher levels of polysorbate 20 reduce dishing in silicon oxide trenches.

Example 3

This example illustrates 1) the removal rate of silicon oxide from the blanket wafer polished with the polishing composition 3A-3L; 2) the removal rate of the polysilicon from the homogeneous polysilicon film (polysilicon blanket wafer) polished with the polishing composition 3A-3L; And 3) various non-ionic surfactants, Igepal CO-890, Igeal CA-630, and wet-process ceria polishing with an average particle size of 30 nm or less on the dishing of the abrasive composition 3A-3L on the patterned wafer Prove the effect of the particles. In this example, the abrasive composition comprises 6000 ppm PEG 8000, various types of non-ionic surfactant (as shown in Table 3), 1000 ppm of cocoa CO-890, and 2.4% of an average particle size of less than 30 nm wet Fair ceria abrasive grains were included. All combinations were tested in 0.43% solids. (1000 ppm in the polishing compositions 3K and 3L were replaced with CA-630 (1000 and 2000 ppm respectively) instead of CO-890).

The hydrophobic-lipophilic balance (HLB) for each non-ionic surfactant is also listed in Table 3.

TEOS, HDP, and polysilicon blanket wafers were polished with a polishing composition 3A-3L. Further, the patterned wafer was polished with the polishing composition 3A-3L. Polishing was carried out on a Mira < (TM) > CMP device (Applied Materials, Inc., Santa Clara, Calif.). Dishing was measured by an F5 ellipsometer polarizer (KLA-Tencor, Milpitas, Calif.).

After polishing, the TEOS, HDP, and polysilicon removal rates for each polishing composition were measured in Å / min. The result is shown in FIG. 4, which is a bar graph showing the removal rate (Y-axis) of the three surface wafer types for a particular polishing composition (X-axis).

The dishing exhibited by each polishing composition was measured in Angstroms and is shown in Figure 5, which is a line graph showing the dishing (Y-axis) measured within a pitch of various lengths (X-axis) for each polishing composition.

Table 3: Polishing composition summary

These results demonstrate that the polishing composition of Table 3 exhibits a high removal rate for silicon oxide while maintaining a much lower removal rate for polysilicon. The selectivity exhibited by polishing compositions 3A-3L is ideal in CMP compositions. For example, the polishing composition 3G exhibited a silicon oxide removal rate exceeding 1600 A / min, but the polysilicon was removed at a rate of 128 A / min. The magnitude of the selectivity exhibited by the polishing composition 3G is an example of all of the polishing compositions in Table 3.

The results also demonstrate that the polishing composition of Table 3 exhibits poor dishing performance. More particularly, Figure 5 illustrates dishing within micrometer pitches of various sizes at 50% density. Even at the smallest pitch size, all polishing compositions exhibited a dishing of greater than 1900 A. Polishing compositions 3H and 3J had the lowest dishing at various pitch sizes. This is because the abrasive compositions 3H and 3J contained the highest amounts of polysorbate 65 and sorbitan 20, respectively, and both were in the more hydrophobic surfactants used in the polishing compositions of Table 3, .

Example 4

This example demonstrates the effect of varying the silicon oxide removal rate from the blanket wafers polished with the polishing composition 4A-4K and the various cationic polymers, non-ionic surfactants, and the like that affect the removal rate of the polysilicon blanket from the polishing composition 4A- And an effect of wet-process ceria abrasive grains having an average particle size of 30 nm or less. In this example, the abrasive composition comprises 6000 ppm PEG 8000, various types of branched PEG and polypropylene glycol (PPG) polymer and polysorbate (as shown in Table 4) and 2.4% wet Fair ceria abrasive grains were included. All combinations were tested in 0.43% solids. The HLB for each non-ionic surfactant is also listed in Table 4.

The blanket wafers of TEOS, HDP, and polysilicon were polished with a set of polishing compositions 4A-4K shown in Table 4 below. Polishing was carried out on a Mira < (TM) > CMP device (Applied Materials, Inc., Santa Clara, Calif.).

After polishing, the TEOS, HDP, and polysilicon removal rates for each polishing composition were measured in A / min. The results are shown in Fig. 6, which is a bar graph showing the removal rates (Y-axis) of the three surface wafer types for a particular polishing composition (X-axis).

Table 4: Polishing composition summary

These results demonstrate that the polishing composition 4A-4I generally exhibits a high silicon oxide removal rate while maintaining a low silicon removal rate. More particularly, the result is that the presence of ethoxylated molecules (e.g., PEG) in polishing compositions 4A-4I is less likely to occur because the removal rate is constant in the polishing composition regardless of the amount of polysorbate that polishing composition 4A- Removal rate data. ≪ / RTI > For example, polishing compositions 4F and 4H exhibited approximately the same silicon oxide removal rate and lower polysilicon removal rate, despite containing different types and amounts of polysorbate.

Polishing compositions 4J and 4K were extremely low and therefore exhibited a less ideal silicon oxide removal rate, as well as a very low polysilicon removal rate. Polishing Compositions 4J and 4K included a comb-type polymer comprising the same amount of Primip PD-4913, PEG side chain, which was probably the reason for the low silicon oxide removal rate in these polishing compositions.

Example 5

This example illustrates 1) the silicon oxide removal rate from the blanket wafer polished with the polishing composition 5A-5D; 2) Polysilicon removal rate from polysilicon blanket wafer polished with polishing composition 5A-5D; And 3) the effect of the thickener on the dishing of the polishing composition 5A-5D on the patterned wafer and the wet-process ceria abrasive grains having an average particle size of 30 nm or less. In this example, the polishing composition includes 6000 ppm PEG 8000, hydroxyethyl cellulose and various types of polysorbates (as shown in Table 5A), and 2.4% wet process ceria abrasive grains having an average particle size of 30 nm or less Respectively. All combinations were tested in 0.43% solids.

TEOS, HDP, and polysilicon blanket wafers were polished with a set of polishing compositions 5A-5D. Further, the patterned wafer was polished with the polishing composition 5A-5D. Polishing was performed on a Reflection CMP device (Applied Materials, Inc., Santa Clara, Calif.). Dishing was measured by an F5 ellipsometer polarizer (KLA-Tencor, Milpitas, Calif.).

After polishing, the TEOS, HDP, and polysilicon removal rates for each polishing composition were measured in A / min. The results are shown in Table 5B below, which is a chart listing both the silicon oxide and polysilicon removal rates for each polishing composition in A / min. After polishing, the dishing exhibited by each polishing composition was measured in A and is shown in Table 5B.

Table 5A: Polishing composition summary

Table 5B: Polishing performance for polishing compositions 5A-5D

These results demonstrate that the presence of the thickener hydroxyethylcellulose in the polishing compositions 5A-5D caused a significantly lower occurrence of the dicing rate, especially in the polishing compositions 5C and 5D. In particular, polishing composition 5D exhibited less than 100 Angstroms of dishing while maintaining a silicon oxide removal rate of greater than 1000 Angstroms per minute and a very low polysilicon removal rate. This data shows that hydroxyethylcellulose provides a solution to the high dicing rate that was present in Examples 2 and 3 while maintaining an ideal removal rate for both silicon oxide and polysilicon.

The polishing composition of this example generally exhibited an ideal removal rate and a lower dicing rate, but the particle residues remained on the blanket wafer surface tested. Residues that remain on the blanket wafer after polishing are complete impair the ability to test the wafer surface for scratches.

Example 6

This example illustrates 1) the silicon oxide removal rate from the blanket wafer polished with the polishing composition 6A-6D; 2) Polysilicon removal rate from polysilicon blanket wafer polished with polishing composition 6A-6D; And 3) the wettability of the cationic polymer poly MADQUAT on the defect count (DCN) exhibited by the abrasive compositions 6A-6D on the blanket wafer and the wet-process ceria abrasive grains having an average particle size of 30 nm or less. This effect was also compared to the control abrasive composition. In this embodiment, the polishing composition comprises 6000 ppm PEG 8000, 660 ppm polysorbate 85, triethanol amine (400 or 600 ppm), cationic polymer poly MADQUAT (Alco 4773, 20 or 50 ppm) Of 2.4% wet process ceria abrasive grains of average particle size. All combinations were tested in 0.43% solids.

7 and 8, the control group contained 600 ppm hydroxyethylcellulose, 1320 ppm polysorbate 85, and 400 ppm triethanolamine.

The blanket wafers of TEOS, HDP, and polysilicon were polished with a set of polishing compositions 6A-6D and a control polishing composition. Polishing was carried out on a Mira < (TM) > CMP device (Applied Materials, Inc., Santa Clara, Calif.).

After polishing, the TEOS, HDP, and polysilicon removal rates for the polishing compositions 6A-6D and the control polishing composition were measured in A / min. The result is shown in FIG. 7, which is a bar graph showing the removal rates (Y-axis) of the three surface wafer types for a particular polishing composition (X-axis).

The DCN results are shown in FIG. 8, which is a box plot of the random defect count (Y-axis) at two different thresholds (0.16 and 0.3 micrometers) for each polishing composition (X-axis). A defect count was generated using scanning electron microscopy (SEM) to detect scratches on the wafer surface after polishing.

Table 6: Polishing composition summary

These results demonstrate that adding Alco-4773 to polishing compositions 6A-6D served to reduce the defect count when compared to controls that did not contain Alco-4773. In particular, polishing compositions 6A and 6C exhibited a higher silicon oxide removal rate than the control while maintaining a lower polysilicon removal rate. Polishing compositions 6A and 6C also showed a significant reduction in defect counts compared to the control for defects measured at 0.16 micrometer threshold.

Polishing compositions 6B and 6D, including 50 ppm Alco-4773, showed very low defect counts at both 0.16 and 0.3 micrometer threshold values as compared to the control and the presence of Alco-4773 significantly reduced the defect count To provide additional support.

Example 7

This example illustrates 1) the silicon oxide removal rate from the blanket wafer polished with the polishing composition 7A-7D; 2) Polysilicon removal rate from polysilicon blanket wafer polished with polishing composition 7A-7D; 3) the spin-on-glass (SOG) removal rate from the SOG blanket wafer polished with the polishing composition 7A-7D; And 4) the effect of hydrophobic surfactant hydropallate 3323 and wet-process ceria abrasive grains having an average particle size of 30 nm or less on DCN counts indicated by abrasive compositions 7A-7D on blanket wafers polished with abrasive compositions 7A-7D . This effect was also compared to the control abrasive composition.

In this example, the polishing composition comprised 6000 ppm PEG 8000, 120 ppm triethanolamine, hydrophobic surfactant hydro-palatal 3323 (750 or 1500 ppm), and 2.4% wet-process ceria abrasive grains having an average particle size of 30 nm or less . All combinations were tested in 0.43% solids.

In the following Table 7B, the control group contained 1000 ppm bovine CO890, 500 ppm polysorbate 20, and 120 ppm triethanolamine.

The blanket wafers of TEOS, SOG, HDP, and polysilicon were polished with a set of polishing compositions 7A-7D and a control group. Polishing was carried out on a Mira < (TM) > CMP device (Applied Materials, Inc., Santa Clara, Calif.).

After polishing, the TEOS, HDP, SOG, and polysilicon removal rates for the polishing compositions 7A-7D and the control polishing composition were measured in A / min. The results are shown in Table 7B.

In addition, the DCN counts of polishing compositions 7A-7D were compared to the control at a 0.16 micrometer threshold. A defect count was generated using an SEM to detect scratches on the wafer surface after polishing. The results are also shown in Table 7B.

Table 7A: Polishing composition summary

Table 7B: Removal Rate and Defect Performance for Polishing Composition 7A-7D

These results demonstrate that the addition of hydro-pallat 3323 to polishing compositions 7A-7D served to reduce the defect count when compared to a control that did not contain Hydro-Palat 3323. [ In particular, polishing composition 7A maintained a high silicon oxide removal rate, a low polysilicon removal rate, and a high SOG removal rate, while showing a significantly reduced defect count as compared to the control.

Abrasive composition 7C, which had the highest defect counts in polishing compositions 7A-7D, still had a defect count that was approximately 10 times less than the control and provided additional support that the hydro-palate 3233 served to reduce the defect count.

All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference as if fully set forth herein .

The use of the term singular representation and similar referents in the context of describing the invention (particularly in the context of the following claims) should be construed to include both singular and plural, unless otherwise indicated herein or otherwise clearly contradicted by context do. Unless otherwise indicated, the terms " including, "" having," " including, " and "comprising" are to be construed as being open-ended terms (i. E. Reference herein to a range of values, unless otherwise indicated herein, is intended to serve as a shrinking method that individually refers to each individual value falling within its scope, and each individual value is referred to individually herein Are included in the specification as if they were. All methods described herein may be performed in any suitable order, so long as they are not otherwise indicated herein or otherwise clearly contradicted by context. Use of any and all embodiments, or exemplary language (e.g., "an example, ") provided herein is for the purpose of clarifying the invention only and is not intended to limit the scope of the invention I do not. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

Preferred embodiments of the invention are described herein, including the best mode known to the inventors for carrying out the invention. Modifications of such preferred embodiments may become apparent to those skilled in the art upon reading the foregoing description. The inventors expect that the skilled artisan will make appropriate use of these variations, and the inventors intend that the invention be practiced otherwise than as specifically described herein. Accordingly, the present invention includes all modifications and equivalents of the subject matter protected by the claims appended hereto as permitted by applicable law. Furthermore, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims (26)

(a) wet-process ceria abrasive grains having an average particle size of 30 nm or less;
(b) at least one alcohol amine; And
(c) Water
Wherein the chemical-mechanical polishing composition has a pH of at least 6. The abrasive composition of claim 1, wherein the abrasive particles have an average primary particle size of 12 nm or less. The polishing composition of claim 1, wherein the abrasive particles are present in an amount of from 0.001% to 2% by weight of the composition. The polishing composition of claim 1, wherein the alcohol amine has a pKi of from 6 to 10. The polishing composition according to claim 1, wherein the alcohol amine has a functional group having a pKa of 7 to 11. The process according to claim 1 wherein the alcohol amine is selected from the group consisting of 2-dimethylamino-2-methylpropanol, triethanolamine, diethanolamine, ethanolamine, 2-amino- ≪ / RTI > and any combination thereof. The polishing composition of claim 1, wherein the alcohol amine is present in an amount of from 0.001% to 1% by weight of the composition. The polishing composition of claim 1, further comprising at least one nonionic surfactant. The polishing composition of claim 8, wherein the nonionic surfactant has a hydrophobic lipophilic balance of 7 to 18. The polishing composition of claim 8, wherein the nonionic surfactant comprises polysorbate, sorbitan, polyoxyethylene ether, ethoxylate, acrylic, polyether polyol, or any combination thereof. The composition of claim 8, wherein the nonionic surfactant is selected from the group consisting of polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80, sorbitan monolaurate, polyoxyethylene (40) nonylphenyl ether, pentaerythritol Glycerol propoxylate-block-ethoxylate, acrylic copolymer, polypropylene oxide-based triol, or any combination thereof. The polishing composition of claim 8, wherein the nonionic surfactant is present in an amount of from 0.001% to 1% by weight of the composition. The polishing composition of claim 1, further comprising a thickener. 14. The polishing composition of claim 13, wherein the thickener comprises a cellulosic compound, dextran, polyvinyl alcohol, carrageenan, chitosan, or any combination thereof. 14. The polishing composition of claim 13, wherein the thickener comprises hydroxyethyl cellulose, carboxyethyl cellulose, hydroxymethyl cellulose, methyl cellulose, hydroxypropyl cellulose or any combination thereof. 14. The polishing composition of claim 13, wherein the thickener is present in an amount of from 0.001% to 1% by weight of the composition. The polishing composition of claim 1, further comprising a nonionic surfactant. The polishing composition of claim 1, further comprising a cationic polymer. 19. The polishing composition of claim 18, further comprising a thickener. 19. The method of claim 18 wherein the cationic polymer is selected from the group consisting of poly (methacryloxyethyltrimethylammonium) chloride (poly MADQUAT), poly (diallyldimethylammonium) chloride (poly DADMAC), poly (acrylamide) Poly (vinyl imidazolium), poly (vinyl pyridinium), or any combination thereof. 19. The polishing composition of claim 18, wherein the cationic polymer is present in an amount of from 0.001% to 1% by weight of the composition. 19. The polishing composition of claim 18, further comprising a nonionic surfactant. (i)
Polishing pad, and
(a) wet-process ceria abrasive grains having an average particle size of 30 nm or less;
(b) at least one alcohol amine; And
(c) Water
With a polishing composition having a pH of at least 6;
(ii) polishing the substrate by moving the polishing pad and polishing composition relative to the substrate, thereby worn at least a portion of the substrate
≪ / RTI > wherein the substrate is chemically-mechanically polished. 24. The method of claim 23 wherein the substrate comprises polysilicon and silicon oxide and at least silicon oxide is removed from the substrate to polish the substrate. 25. The method of claim 24 wherein more silicon oxide is removed from the substrate at a higher rate than the polysilicon. 26. The method of claim 25, wherein the removal rate from the substrate to silicon oxide is at least 10 times greater than the removal rate for polysilicon.

Images